Combustor Wall Bond Coat with Networked Ceramic Nanofibers

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Solution Overview

Problem

Gas turbine engine components in the core gaspath face extreme temperatures that existing cooling features and barrier coatings struggle to adequately manage, particularly in terms of thermal insulation and corrosion resistance.

Innovation Solution

A combustor wall with a substrate coated by a bond coat layer of MCrAlY and a layer of networked ceramic nanofibers, where the nanofibers form a tangled porous network for enhanced thermal insulation and physical sealing, comprising materials like zirconium oxide or yttria stabilized zirconia, fabricated using a blow-spinning process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If traditional ceramic barrier coatings are used to protect the substrate from extreme temperatures, then thermal insulation is provided, but the coatings are heavy and less efficient

Engineering Contradiction:
Improvethermal insulation performanceVSAvoidcoating weight
Core Design Contradiction:
TemperatureVSWeight of moving object

Solution Approach 1:

The patent employs a porous ceramic coating layer with controlled porosity (30-70%) to provide thermal insulation. The porous structure reduces the density and weight of the coating while maintaining effective thermal barrier performance, as the air pockets within the porous structure inhibit heat transfer

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The patent uses a composite coating system consisting of a metallic bond coat layer (MCrAlY) and a ceramic barrier coat layer (such as Yttria-Stabilized Zirconia or Gadolinia Zirconate). This composite structure combines the advantages of both materials: the bond coat provides oxidation resistance and thermal barrier properties, while the ceramic layer provides superior thermal insulation, achieving lightweight high-temperature protection

Inventive Principle:
Principle #40Composite materials

2Temperature

If barrier coatings are applied to protect from extreme temperatures, then thermal protection is improved, but corrosion resistance from environmental factors remains insufficient

Engineering Contradiction:
Improvethermal protectionVSAvoidcorrosion resistance
Core Design Contradiction:
TemperatureVSObject-affected harmful factors

Solution Approach 1:

The patent employs a composite coating system with a metallic bond coat layer (MCrAlY) providing oxidation resistance and a ceramic barrier coat layer (such as Yttria-Stabilized Zirconia or Gadolinia Zirconate) providing thermal insulation. This composite structure simultaneously addresses both thermal protection and corrosion resistance requirements

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent modifies the chemical composition parameters of the bond coat layer by using MCrAlY alloys with specific ratios of metals, and the ceramic layer with specific stabilizers (yttria or gadolinia), to enhance both thermal and corrosion resistance properties through controlled material parameters

Inventive Principle:
Principle #35Parameter changes

3Temperature

If cooling features and barrier coatings are used to protect the substrate, then thermal protection is provided, but the system complexity increases

Engineering Contradiction:
Improvesubstrate protectionVSAvoidcooling and coating system complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the need for complex active cooling systems by providing passive thermal protection through the bond coat and ceramic barrier coating layers. The coating system alone is sufficient to protect the substrate from extreme temperatures, simplifying the overall system design

Inventive Principle:
Principle #2Taking out (Extraction)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution provides superior thermal insulation and physical sealing, effectively protecting the substrate from high temperatures and environmental damage, while being lighter and more efficient than traditional ceramic thermal barrier coatings.

Implementation Method 1

A combustor wall with a substrate coated by a bond coat layer of MCrAlY and a layer of networked ceramic nanofibers, where the nanofibers form a tangled porous network for enhanced thermal insulation

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 2

the nanofibers form a tangled porous network for enhanced thermal insulation and physical sealing, in which the pores are voids

Methodology Applied
Scientific EffectPorosity: Porosity

Data Source

PatentEP3693489B1A combustor wall with bond coat layer and layer of networked ceramic nanofibers
Publication Date: 2023.08.23 RTX CORP

AI summary

An article includes a substrate (74), a bond coat layer (78) disposed on the substrate (74), and a layer (80) of networked ceramic nanofibers (82) disposed on the bond coat layer (78).